Fatalities on American roadways are on the rise and smartphones may be at least partially to blame, according to the National Highway Transportation Safety Administration (NHTSA).

Deaths on American roadways increased 7.2 percent percent in 2015, according to the group, representing the biggest single-year increase since 1966.

Exactly what role smartphones may have played in these 35,092 deaths is difficult to determine. The primary culprit behind this increase in fatalities, according to their report, is actually the improving economy (people drive more when they have more money). Consistently rising speed limits on the nation’s highways may also bear a large part of the blame.

The problem: the data doesn’t paint such a grim picture. Of the fatal traffic accidents recorded by the NHTSA in 2015, only about 10 percent were caused by the broad category of “distracted driving,” and smartphone use would be subset within that that 10 percent.

Smartphone use on the road is a real â and growing â problem.

Still, smartphone use on the road is a real â and growing â problem, and one the government is right to be concerned about.Â

In 2014, the most recent year the agency collected data around distracted driving, at least 13 percent of “distraction-affected”fatalities were “directly linked” to the use of a phone. That may sound like a relatively small amount compared to the number of overall accidents, but the number of phone-linked incidents has grown quickly as smartphones become increasingly common. The NHTSA notes that during that same year at least 33,000 people were injured in crashes linked to mobile phone use.

In order to bring these numbers down, the NHTSA is looking to enlist the tech industry for help. Last week, the agency proposed a new set of guidelines meant to encourage phone manufacturers and others to design devices and apps with driver safety in mind. These guidelines, however, may not go far enough.

Under the proposal, handset makers and operating system developers would voluntarily create a specific “driver mode” for devices. Driver mode would switch the phone’s user interface to a pared-down, driving-friendly design when you’re in the car (think, Google’s standalone Android Auto app, which strips out everything other than a handful of services you may need while in the car, like maps and music.)

Google’s standalone Android Auto app.

The proposal notes that, for now, any driver mode would likely have to be manually enabled. The problem with this, of course, is that it requires drivers manually change their settings each time they get in the car, meaning drivers can simply (and probably will) not use it. (The proposal call refers to this as a “temporary” measure until technology improves enough for this to be done automatically, which is the preferred method.)

“NHTSA has learned that technologies to detect whether a driver or passenger is using a device have been developed but are currently being refined such that they can reliably detect whether the device user is the driver or a passenger and are not overly annoying and impractical,” the proposal says.

Detecting whether or not you’re in a moving vehicle based on phone sensors and GPS is now routine.

The NHTSA may be underestimating current smartphone technology. Apple has been building numerous sensors and a “motion coprocessor” in the iPhone for years, and Motorola offered an automatically triggered Driving Assist mode as far back as 2014. While discerning between passengers and drivers is indeed difficult, detecting whether or not you’re in a moving vehicle based on phone sensors and GPS technology is now routine.

The proposal also ignores the sad fact that device makers (outside of Apple and Google) are notoriously slow to adopt even the most critical system updates and security patches. If we can’t rely on OEMs to make vital security and regular software updates a priority, what hope is there for a voluntary driver safety feature? Looking at progress, self-driving cars â which render the distracting-driving issue moot â will probably come sooner.

Instead of waiting for some kind of technological silver bullet, the NHTSA might have better luck by leaning harder on individual app developers, which push out updates much more reliably. The agency does say its making efforts to reach out to developers, but it should be the primary emphasis, not an afterthought.Â

As it stands now, most apps do little to discourage use while driving. In-app warnings around driver safety are relatively rare and rarer still are built-in safeguards that prevent use at driving speeds.

Snapchat, whose “speed filter” shows how fast you’re traveling at any given moment and has been allegedly linked to serious accidents, also includes warnings. The app displays a “Don’t snap and drive” warning when you use the speed filter, and the app’s terms of service (if you bother to read them) specifically forbid using the app while driving. The company has previously worked with the ad council on a driver safety awareness campaign.

But safety features and warnings like this should be the norm, not the exception. A better solution than relying on device makers would be to target developers of the most popular apps â particularly messaging and social media apps â and incentivize them to include prominent warnings.Â

Yes, developers may balk at the idea of adding intrusive warnings or undertaking a costly redesign to address driver-specific uses, but technology has solved more difficult problems than this. And with accidents on the rise, it’s no exaggeration to say lives are on the line.